/*
 * Copyright (C) 2008 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.android.demo.notepad2;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

/**
 * Simple notes database access helper class. Defines the basic CRUD operations
 * for the notepad example, and gives the ability to list all notes as well as
 * retrieve or modify a specific note.
 * 
 * This has been improved from the first version of this tutorial through the
 * addition of better error handling and also using returning a Cursor instead
 * of using a collection of inner classes (which is less scalable and not
 * recommended).
 */
public class VocablesDbAdapter {

    public static final String KEY_QUESTION = "question";
    public static final String KEY_ANSWER = "answer";
    public static final String KEY_LEVEL = "level";
    public static final String KEY_DUEDATE = "duedate";
    public static final String KEY_ROWID = "_id";
    private static final String DATABASE_NAME = "data";
    private static final String DATABASE_TABLE = "vocables";
    private static final int DATABASE_VERSION = 2;
    
    private static final String TAG = "NotesDbAdapter";
    
    
    private DatabaseHelper mDbHelper;
    private SQLiteDatabase mDb;

    /**
     * Database creation sql statement
     */
    private static final String DATABASE_CREATE =
        "create table "+ DATABASE_TABLE + 
        " ("+
        KEY_ROWID+ " integer primary key autoincrement, " +
        KEY_QUESTION+ " text not null, " +
        KEY_ANSWER+ " text not null, " +
        KEY_DUEDATE+" date not null, "+
        KEY_LEVEL+" int not null);";
    




    private final Context mCtx;

    private static class DatabaseHelper extends SQLiteOpenHelper {

        DatabaseHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {

            db.execSQL(DATABASE_CREATE);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                    + newVersion + ", which will destroy all old data");
            db.execSQL("DROP TABLE IF EXISTS vocables");
            onCreate(db);
        }
    }

    public VocablesDbAdapter(Context ctx) {
        this.mCtx = ctx;
    }

    public VocablesDbAdapter open() throws SQLException {
        mDbHelper = new DatabaseHelper(mCtx);
        mDb = mDbHelper.getWritableDatabase();
        System.out.println(mDb.toString());
        return this;
    }

    public void close() {
        mDbHelper.close();
    }

    public long createVocable(String question, String answer) {
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_QUESTION, question);
        initialValues.put(KEY_ANSWER, answer);
        initialValues.put(KEY_LEVEL, 0);
        //initialValues.put(KEY_DUEDATE, null);

        return mDb.insert(DATABASE_TABLE, null, initialValues);
    }

    /**
     * Delete the note with the given rowId
     * 
     * @param rowId id of note to delete
     * @return true if deleted, false otherwise
     */
    public boolean deleteVocable(long rowId) {

        return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
    }

    /**
     * Return a Cursor over the list of all notes in the database
     * 
     * @return Cursor over all notes
     */
    public Cursor fetchAllVocables() {

        return mDb.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_QUESTION,
                KEY_ANSWER, KEY_DUEDATE, KEY_LEVEL}, null, null, null, null, null);
    }

    /**
     * Return a Cursor positioned at the note that matches the given rowId
     * 
     * @param rowId id of note to retrieve
     * @return Cursor positioned to matching note, if found
     * @throws SQLException if note could not be found/retrieved
     */
    public Cursor fetchVocable(long rowId) throws SQLException {

        Cursor mCursor =

            mDb.query(true, DATABASE_TABLE, new String[] {KEY_ROWID, KEY_QUESTION,
                    KEY_ANSWER, KEY_DUEDATE, KEY_LEVEL}, KEY_ROWID + "=" + rowId, null,
                    null, null, null, null);
        if (mCursor != null) {
            mCursor.moveToFirst();
        }
        return mCursor;

    }

    /**
     * Update the note using the details provided. The note to be updated is
     * specified using the rowId, and it is altered to use the title and body
     * values passed in
     * 
     * @param rowId id of note to update
     * @param title value to set note title to
     * @param body value to set note body to
     * @return true if the note was successfully updated, false otherwise
     */
    public boolean updateVocable(long rowId, String question, String answer) {
        ContentValues args = new ContentValues();
        args.put(KEY_QUESTION, question);
        args.put(KEY_ANSWER, answer);

        return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
    }
}
